The invention relates to apparatus for controlling the tool position of a machine tool, comprising data memory means for storing tool position data in a given sequence and tool adjustment speed data, means for entering said tool position data and tool adjustment speed data into said data memory means, means for retrieving said data for controlling the tool movement to positions determined by said tool position data with adjustment speed determined by said tool adjustment speed data, display means for the visual display of the entered position data and adjustment speed data, and means for marking selected ones of said position data and adjustment speed data displayed on said display means, and at the same time of the associated storage position in said data memory means.
In modern machine tool control devices used for instance in plastic processing machines such as blow molding machines, injection molding machines and the like, the process parameters are entered and issued with the aid of a keyboard and a visual display, respectively. The visual display may comprise a viewing screen or, in a simplified form, an LED line display, a liquid crystal line display of the like. The process parameters, that is, data corresponding to the positions to be assumed by the tool during the process, and data relating to the adjustment speeds at which the tool is to be adjusted between the individual given positions, are entered by an operator via the keyboard and displayed on the display device in tablular form for instance. If a parameter is to be altered, the respective parameter can be selected by entering the associated serial number or by positioning a marker at the respective data, which goes together with the marking of the associated storage position in the memory means. The selected parameter may then be overwritten by entering new data by means of the keyboard.
In many processes, for instance in the plastic processing industry, there are numerous parameters which cannot be accurately predicted, for instance by calculation. These parameters rather have to be determined by extensive trials, to which purpose they are initially altered by way of approximation, and subsequently altered in the course of the process until the optimum value is found. This is frequently accomplished by applying empirical values for altering the selected parameter either by an absolute amount or by a determined fraction of its actual value. This requires the selected actual parameter to be read out, however, and to be re-entered after its altered value has been calculated on the base of its actual value. This is a time-consuming and cumbersome operation and a possible source of errors.
In practice it is therefore customary to do without this calculation and to estimate and re-enter the altered value of the selected parameter. This estimating procedure gives frequently reason, however, for numerous futile trials. In addition, this estimating method is also time-consuming, because the estimated altered value of the parameter has to be entered at full length, which may require the operation of a great number of keys on the keyboard.